I have a weber gold c grill and really like it. I preheat (all 3 burners on high) the grill befor i use it but I know it is just a matter of time untill i forget that the grill is heating. I have let it go (550F+) for 5 minuts or so in the past. Can I destroy the grill of thermometer if i let it go longer??? Thanks for the info.

You've got a high quality grill on your hands, that I know for certain. Beyond that I'm no grill professional and designer (thats my disclaimer), but I've had my weber peaked out before at close to 700. Mine still runs great. I'd say that as long as you're dealing with a quality grill, which you are, they are designed to handle heat. You should be fine.

I have gotten propane grills really. really hot before and nothing has happened. The body of the grill will not be damaged. Remember that the surface temperature of charcoal can reach upwards of 1800 degrees. Eventually this will burn through even protected grills but this takes years at temperatures much hotter that propane can reach. The only question is the burners, my guess is that they can take anything that propane can dish out.

As long as you have not altered the grill or specifically the burners in any way you will be fine. Weber selected the burner to fit that grill and will stand behind any product that they build (as long as you have not altered any part or used non Weber replacement parts)